Design of a Flexible Generator Rejection Scheme and Its Risk Assessment

In a power system, some disturbances can cause abnormal system conditions leading the system to huge damages. Special protection systems (SPS) can detect these abnormal conditions and initiate pre-planned corrective action to mitigate their consequences. However, excessive reliance on SPS can result in increased risk. In this paper, a flexible generator rejection scheme (GRS) for Tehran Transmission System is designed. Using the results of the system transient stability simulation and reliability evaluation of GRS, risk assessment of this scheme is made. Based on this assessment, economic effects of this GRS are analyzed. Furthermore, two methods for making GRS-related decisions are proposed and compared with each other.